Flavor Text in Games

How much flavor text do you use in game design? In abstract games this is a non issue, but in games with a theme how much is too much? Do you rely on some, or do you just use the pieces and board itself for the flair?

The best use of flavor text, the one that I enjoy the most and makes the most sense is incorporating it into the rules where the idea of so many good games it to convey a theme. Games like Princes of Florence, Tikal, Mexica, Puerto Rico all convey a degree of rules-base flavor text to help the players understand how the mechanics of the games are more than simple abstractions, but are indeed tied intricately into the premise of the game. To me, tying flavor text into the rules to convey theme is flavor text at it